Interfacial Charge Contributions to Chemical Sensing by Electrolyte-Gated Transistors with Floating Gates

Mathew S. Thomas, Scott P. White, Kevin D. Dorfman, C. Daniel Frisbie

Research output: Contribution to journalArticlepeer-review

19 Scopus citations

Abstract

The floating gate, electrolyte-gated transistor (FGT) is a chemical sensing device utilizing a floating gate electrode to physically separate and electronically couple the active sensing area with the transistor. The FGT platform has yielded promising results for the detection of DNA and proteins, but questions remain regarding its fundamental operating mechanism. Using carboxylic acid-terminated self-assembled monolayers (SAMs) exposed to solutions of different pH, we create a charged surface and hence characterize the role that interfacial charge concentration plays relative to capacitance changes. The results agree with theoretical predictions from conventional double-layer theory, rationalizing nonlinear responses obtained at high analyte concentrations in previous work using the FGT architecture. Our study elucidates an important effect in the sensing mechanism of FGTs, expanding opportunities for the rational optimization of these devices for chemical and biochemical detection.

Original languageEnglish (US)
Pages (from-to)1335-1339
Number of pages5
JournalJournal of Physical Chemistry Letters
Volume9
Issue number6
DOIs
StatePublished - Mar 15 2018

Bibliographical note

Funding Information:
Part of this work was carried out in the College of Science and Engineering Characterization Facility, University of Minnesota, which received capital equipment funding from the NSF through the UMN MRSEC program under Award Number DMR-1420013.

Funding Information:
The authors thank Greg Haugstad for conducting the NRA study and Abel Demissie for discussions regarding analysis of the NRA. We acknowledge funding from the Office of Naval Research through the Multi-University Research Initiative (CDF). A portion of this work was performed at the University of Minnesota Nanofabrication Center, which received partial support from the NSF through NNIN. Part of this work was carried out in the College of Science and Engineering Characterization Facility, University of Minnesota, which received capital equipment funding from the NSF through the UMN MRSEC program under Award Number DMR-1420013.

Publisher Copyright:
© 2018 American Chemical Society.

How much support was provided by MRSEC?

  • Shared

Reporting period for MRSEC

  • Period 5

PubMed: MeSH publication types

  • Journal Article

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